I would ask for an itemized bill for the vet visit… and while the show invoice was transparent and appears appropriate, I am less comfortable with the vet bill if OP doesn’t know what the charges were for.
I find it a bit perplexing that a PPE would be billed to a client who was unaware of its being done, or of the outcome/findings. The whole point is to know what you’re getting into. I also don’t know that a six month short stirrup lease would necessitate a PPE. I don’t recall if I did a PPE on my now owned mare pre-lease (and she was showing 1.20 and schooling higher before she came to me, not short stirrup!), but if I did, it was very basic and included no rads. I did, of course, do a thorough PPE with rads before purchasing her. I just cannot imagine a scenario where I, as a client, would be okay with being charged for an exam I was not aware of, much less had access to the findings thereof.
I also don’t know that I would be particularly pleased with paying for maintenance if its requirement and cost were not disclosed to me in advance. I actually DID pay for maintenance when I leased my horse, but I was aware it might be necessary, and of how much it would set me back… and I was part of the decision to do it.
I don’t like surprises, but I am also not new to horses and know what questions to ask up front. Sound healthy horses without maintenance requirements who don’t injure themselves or get sick are unicorns and anything can happen… but I want to know an animal’s history before signing up to foot its bill. One who needs vaccinations, dental and Coggins but unless it tries to kill itself (like they all do) is not gonna eat my earnings in vet bills is a different calculation than one with known issues. Which brings me back to the PPE…
Either way, the OP should know what the $1k was for.